Retailers of goods and services typically offer such goods and services for purchase via one or more conventional brick-and-mortar retail stores. In such stores, items for purchase are typically stocked in quantity on shelving and/or display units, and visiting customers typically select desired items for purchase from such shelving and/or display units. From time to time, an item that a customer wishes to purchase may not be stocked in a sufficient quantity on a shelving and/or display unit to satisfy the customer's needs, or may be completely missing from its stock location on the shelving and/or display unit, i.e., “out-of-stock.” It may therefore be desirable for retailers to provide one or more mechanisms by which a customer can obtain a desired quantity of an item that is out-of-stock or that is not stocked in sufficient quantity to satisfy the customer's needs.